Electrical relay



July 21, 1931. s. RUBEN ELECTRICAL RELAY Filed Dec. 6. 1927 Patented July 21, 1931 UNITED STATES SAMUEL RUBEN, OF NEW YORK, N. Y., ASSIGNOR TO RUBEN PATENTS COMPANY, OF

PATENT OFFICE NEW YORK, N. Y., A CORPORATION OF DELAWARE ELECTRICAL RELAY Application filed December 6, 1927. Serial No. 238,218.

This invention relates to an electrical relay and more particularly to an evacuated tube functionmg through the expansion and contraction of lts cathode, responslve to lOIllO bombardment.

The object of the invention is the provision of a relay device of this general character, by which the relay control is achieved through the utilization of thermal effects produced 10 by variations in the ionic bombardment of the cathode.

The invention is an improvement upon that described in my prior and copending application, bearing Serial Number 180,909,upon

a cathode sensitively responsive to ionic bom- 0 present device functions wholly by the thermal efiect of the ionic bombardment upon the cathode.

Reference is also made to my other and copending patent applications which Ihave filed in the United States Patent Oifice, bearing Serial Numbers 534,213; 551,678 ;754,957 23,581; and 155,541, all of which employ the effect of the electronic bombardment of an anode from the cathode to effect the opening and closing of an external circuit contact gap located within a vacuum tube.

Where the thermal effect of ionic bombardment is employed to give the maximum speed in opening and closing a contact gap through the contraction and expansion of the cathode element, it is necessary that the thermally responsive cathode element should be of the smallest practicable mass and operated at the highest practicable temperature to give maximum radiation, and preferably bein a low pressure gaseous atmosphere. A low pressure gas, preferably argon, in the tube allows a rapid dissipation of energy from the filaments and permits ionic bombardment.

A difficulty met in operating this type of relay is the absence of any practicable means for adjusting the contact gap space. This difliculty has been overcome by having the cathode in two parts, one capable of elec- 5o tronic emission, and therefore subject to ionic bombardment and adapted to ready expan sionand contraction, responsive to such bombardment and the other, beyond the direct range of and not responsive to the ionic bombardment, and which is used only for adj usting the contact gap space by the heat normal- 1y applied to it.

Reference is made to the accompanying drawings illustrating one embodimentof the invention in which Fig. 1 diagrammatically shows a low pressure gas tube containing argon in which are the usual vacuum tube elements, Fig. 2 is a plan view of the three electrodes at section 2-2 of Fig. 1.

Referring to Fig. 1 at 1 is a filament cathode coated with barium-strontium oxides for high electron emission, and against which there is an ionic bombardment from anode 3, both streams being controlled by the potential of grid 2. Cathode 1 is supported under tension by molybdenum spring 1 which also acts as the lea-d-inwire for the heating current to the electron emission and the adjust ment filaments. Above filament 1 is a length of nickel-chromium wire, the adjustment filament supported under tension by tungsten spring 1 and which is heated for the desired adjustment of the gap between contacts 4 and 4a, independently of the temperature of the cathode 1, which is supported by conducting rods 1 and 1,. Grid 2 is mounted on conducting rod 2 and anode 3 is supported by insulated rod 3 and conducting rod 3 Conducting rod 1 supports spring 1; and is one of the leads in the external or local circuit to be controlled by the opening and closing of the gap between contacts 4 and 4 the latter mounted on conducting rod 4,, which is the other lead in the local circuit. Besides being a lead in the local circuit, conductor rod 1 is a lead in the circuit for heating filamission of the argon gas which should be as pure as possible.

The elements of a radio receiving circuit and of a local or bell-ringing circuit are conventionally shown by Fig. 1 in which '1 represents an input coil, into which electrical oscillations are induced; B is the source of potential for maintaining the grid at a negativepotential in respect to filament 1. At B is a source of potential for supplying the ionization potential, making possible an ionic discharge between anode 3 and cathode 1. B is a source of potential for heating the cathode l to emission temperature and for heating the gap adjusting section 1, of the composite filament. R and R1 are variable resistances for adjusting their respective circuit currents; L represents the local circuit in which a bell is connected to be operated by the closing of the contact gap 4 1A.

In operation, as the cathode filament is heated by battery B and by the ionic bcm bardment resulting from the application of the B potential. The contact gap is adjusted by the resistor R until the expansion of the non-emission section 1 of the filament brings the contact 4 close to the contact 4,. The increased electron stream obtained by the application of a potential to the grid circuit, especially when positive, allows an increase of electronic and ionic flow, with an increase of ionic bombardment on the catnode, causing by its expansion the gap to close and operate the local circuit.

What I claim is:

1. A thermionic relay comprising an envelope containing argon at low pressure, and anode, grid and thermionic-cathode elements, a fixed contact element and a movable contact element, all of said elements having external terminals, and said movable contact element being connected to said thermionic cathode element for movement therewith responsive to ionic bombardment of said cathode element.

2. A thermionic relay comprising an envelope containing a monatomic gas at low pressure, and anode, grid and thermionic cathode elements, a fixed contact element and a movable contact element, all of said elements having external terminals and said movable contact element being connected to said thermionic cathode element for movement therewith responsive to variations in the ionic bombardment of said cathode element by variations in electrical impulses impressed upon said grid.

3. A thermionic relay comprising an envelope containing a monatomic gas at a low pressure and anode, grid and thermo-expansible thermionic-cathode elements a fixed contact element and a movable contact element, all of said elements having external terminals, and said movable contact element being connected to said thermionic cathode element for movement therewith responsive to ionic bombardment of said cathode element.

4:. A thermionic relay comprising an envelope containing a monatomic gas at low pressure, and anode, grid and thermo-expansible thermionic-cathode elements, a fixed contact element and a movable contact element, all of said elements having external terminals, and said movable contact element being connected to said thermionic cathode element for movement therewith responsive to ionic bombardment 01". a portion of said cathode element, the normal position of said movable contact element being controlled by the discharge of current through another portion of said cathode element.

5. A thermionic relay comprising an envelope containing a monatomic gas at low pres sure, and anode, grid and thermionic-cathode elements, a fixed contact element and a movable contact element, all of said elements having external terminals, and said movable contact element being connected to said thermionic cathode element for movement therewith responsive to ionic bombardment of said cathode element.

in testimony whereof, SAMUEL RUBEN has signed his name to this specification this 5th day of December, 1927.

SAMUEL RUBEN. 

